A conventional bed frame has two opposed side rails extending between a footboard and a headboard. These side rails may be made of any material but are most often made of metal or wood. The side rails often have a flat horizontal flange extending inwardly from a vertical portion. In order to support the weight of a box spring and mattress, a plurality of transversely extending wooden or metal slats often were inserted between the side rails and rested on the horizontal flanges of the side rails. However, such transversely extending slats often warped, twisted outwardly or deflected under the weight of the box spring and mattress placed on top of the rails. As wider span-size beds such as a queen size bed which is 60″ standard width or a king size bed which is 76″ standard width became more popular, the wooden slats had to become longer and wider. The problem of twisting or torquing slats increased and in addition, the two opposed side rails tended to twist or turn outwardly as well due to the weight placed on the slats.
U.S. Pat. No. 4,080,674 discloses a center cross bar extending transversely of two opposed side bed rails which eliminates the need for transversely extending slats. The center cross bar is provided with two vertically adjustable supporting leg assemblies, each leg assembly having a vertically adjustable glide or foot at the lower end thereof. The glides contact a floor or other supporting surface to support the cross bar so as to prevent sagging of a box spring placed thereon and prevent any vertical deflection, horizontal deflection and twisting or torquing of the opposed side rails of the bed frame. Such a vertically adjustable supporting leg assembly incorporated into a cross bar enabled the two opposed bed rails or side rails to be pulled into a snug engagement with a box spring over a substantial portion of the length of the box spring in order to provide a firm support for the box spring along the bottom side and center portion of the box spring without having to utilize transversely extending removable slats.
U.S. Pat. No. 5,203,039 discloses a cross bar adjustable in length as well as height adapted to extend between two wooden side rails of a bed frame. The cross bar has multiple legs which are pivotally connected to the cross bar and capable of pivoting upwardly into a nesting relation with the cross bar for ease of packaging and/or shipping. The legs are also capable of being pivoted downwardly and secured in an erect position. In addition, this patent discloses a cross bar which is adjustable in length because the cross bar comprises two nestable sections each comprising an “L” shaped angle iron. The sections may be pulled apart to increase the length of the cross bar to fit a king or queen size bed and an overlapped, nested portion of the sections secured with a clamp and thumb screw.
U.S. Pat. Nos. 6,209,155 and 6,397,413 each disclose adjustable or extensible cross bars or members for bed rails and frames similar to the adjustable cross bars disclosed in U.S. Pat. No. 5,203,039. Like the cross bars disclosed in U.S. Pat. No. 5,203,039, the cross bars disclosed in U.S. Pat. Nos. 6,209,155 and 6,397,413 are adjustable in length. Each cross bar comprises two pieces, each piece having an L-shaped cross-sectional configuration. The pieces or members of each cross bar are joined in an overlapped or nested region with a clamping member. Each piece or member has a leg which can be adjusted in order to change the height of the cross bar relative to the supporting surface or floor.
The clamping member disclosed in U.S. Pat. No. 5,203,039 uses a thumb screw which passes through a threaded opening in the clamping member to secure the overlapping members together. Use of a clamping member like the one disclosed in U.S. Pat. No. 5,203,039, may allow the angle iron pieces to slide or move laterally undesirably or possibly even separate from each other if the thumb screw becomes loose over time.
The clamping member disclosed in U.S. Pat. Nos. 6,209,155 and 6,397,413 uses lances which engage openings in the angle iron pieces or cross member pieces to lock the clamp and pieces together. Such a clamping member makes separating the pieces of angle iron difficult and may require the use of a special tool to separate the pieces to move the bed. The manufacture of such a clamping member may be expensive due to the formation of the lances.
Typically, each of the pieces or cross members has a leg which may be adjustable in height, as shown in U.S. Pat. No. 6,209,155. However, clamping members used to secure the overlapping portions of the angle iron pieces of each cross bar have been known to have a downwardly depending leg. U.S. Pat. Nos. 6,839,920 and 6,397,413 disclose such clamping members. One difficulty with each of these clamping members is that the leg is fixed in a down position relative to the remainder of the clamping member with rivets or welds. Thus, the leg is not able to be folded into a up position for shipping or other purposes.
Therefore, there is a need for a clamp assembly having a movable leg which keeps the overlapped cross members from slipping or moving relative to each other.